The following patents are incorporated herein by reference in their entirety:
U.S. Pat. No. 6,527,683 discloses an exercise machine having a frame, weight stack, pulleys, and cables and incorporating a dual adjustable pulley system. The weight stack is slidably connected to the frame. A primary moveable pulley system is engaged with the weight stack by way of a primary cable. The primary cable has a handle connected to its first end and its second end is fixed with respect to an exercise movement. A series of directional pulleys are also engaged with the primary cable. The directional pulleys are positioned on the frame to allow for an exerciser to perform multiple exercises employing the weight stack. A secondary moveable pulley system is engaged with the primary moveable pulley system. The secondary moveable pulley system can be selectively engaged with the weight stack using a releasable coupler. A secondary cable is functionally engaged with the secondary moveable pulley system and a number of directional pulleys. The secondary cable has a first end that is fixed to a floating pulley. The floating pulley is functionally engaged with the primary cable. The secondary cable has second end that selectively engages the weight stack. The relationship between the primary moveable pulley system and the secondary moveable pulley system is such that when the handle is moved in an exercise motion, the weight stack provides resistance to the exercise motion.
U.S. Pat. No. 7,717,833 discloses adjustable exercise machines, apparatuses, and systems. The machines, apparatuses, and systems typically include an adjustable, reversible mechanism that utilizes pivoting arms and a floating pulley. The machines, apparatuses, and systems typically are configured for performing pushing and pulling exercises and may provide for converging and diverging motion.